Field
The described technology generally relates to a rechargeable secondary battery.
Description of the Related Technology
With technological advances in mobile devices such as cell phones and laptop computers and increased production yields, demand for secondary batteries has rapidly increased. Recently, research and development in secondary batteries has been actively conducted for use as alternative energy sources that replace fossil fuels as energy sources for electric vehicles or hybrid vehicles.
Secondary batteries generate a large amount of heat during operation and are exposed to external heat during welding when they are manufactured. Electrical properties of secondary batteries change according to thermal deformation or swelling, and thus, their output performance will degrade over time.